The last couple of years have produced research using different nanomaterials that can do the job. Last year, University of Buffalo researchers created silicon nanoparticles that generated hydrogen gas nearly instantaneously when water was added to them. In that process, the nanomaterial didn’t need light or electricity to produce the hydrogen. Of course, the downside was that producing the silicon nanoparticles required a fair amount of energy itself, so it wasn’t clear whether this was a viable solution to overcoming the energy costs of hydrogen production.

“We found that the thickness of the thin film is very important,” says Dr. Linyou Cao, an assistant professor of materials science and engineering at NCSU, in a press release. “A thin film consisting of a single layer of atoms was the most efficient, with every additional layer of atoms making the catalytic performance approximately five times worse.”

The researchers also have indicated that MoS2 thin films have an ideal band gap for solar water splitting. In a Q&A with an NCSU blog, Cao said:

"The band gap of monolayer MoS2 spans over the redox potentials of water. Its valence band is lower than the potential of water oxidation, and the conduction band is higher than that of water reduction. Additionally, its band gap, about 1.8eV, nicely matches the spectrum of solar radiation."